Tube-forming mill



Nov. 19, 1.929.; R, c, ST EL. 1,736,099

File July 14, 1928 5 Sheets Sheet l Nov. 19, 1929. R. c. STIEFEL 1,736,099

TUBE FORMING MILL Filed July 14, 4.928 5 Sheets-Sheet 2 Wzzsa- Nov. 19, 1929. R. c. STIEFEL TUBE FORMING MEIILL Filed July 14, 1928 5 SheetsSheet 5 HiENTOR W, zbuw WIT NESSES WW f'flW Nov. 19, 1929.

M\ 9 wk Nov. 19, 1929. R. c. STIEFEL 1,736,099

14,1928 5 Sheets-Sheet 5 Patented Nov. 19, 1929 UNITED STATES PATENT OFFICE TUBE-FORMING MILL Application filed July 14,

The invention relates to tube-forming mills of the type in which a pair of cross rolls form a pass in which a blank is worked spirally for performing various operations, such as piercing a solid billet, or reducing the wall thick-' ness, increasing the diameter and elongating. a previously pierced or otherwise formed tubular blank.

The object of the invention is to provide a tube-forming mill of the type explained with improved means for laterally adjusting the axes of a pair of cross rolls with relation to each other to vary the pitch of the spiral action of the rolls upon blanks, and with improved means for driving the rolls.

Several embodiments of the invention are illustrated in the accompanying drawings, of which Fig. 1 is a plan View of a mill; Fig. 2 a combined longitudinal central section and side elevation, the plane of view being indicated by the broken line II II, Fig. 1; Figs. 3, 4 and 5 transverse sectlonal views taken, respectively, on the lines IIII II, IV-IV and VV, Fig. 2; Fig. 6 a plan view of a mill embodying modifications of construction; Fig. 7 is a vertical central longitudinal section of the right-hand portion of the mill shown in Fig. 6; Fig. 8. a plan View of a mill embodying further modifications of construction; Fig. 9 a vertical central longitudinal section of the mill shown in, Fig. 8; and Figs. 10 and 11 transverse sectional views taken, respectively, on the lines and -XIXI, Fig. 9.

The tube-forming mill provlded according to this invention has a pair of cross rolls for acting spirally upon the exterior of a cylindrical blank to feed it forwardly over a mandrel held in the pass formed between the working faces of the rolls. Although the rolls may be of various forms, they are preferably of the mushroom type mounted upon the ends of roll shafts whose axes are 1nclined to each other. For varying the width of the pass formed between the rolls so that different diameter blanks may be properly acted upon, the roll shafts are mounted for adjusting'movements longitudinally of their axes.

In .mills of this type it is desirable to pro-' 1928. Serial No. 292,847.

vide means for adjusting the axes of the rolls laterally with relation to each other so that the pitch of the spiral action of the rolls on blanks may be changed depending upon different conditions of operation. According to this invention, at least one, but preferably both, ofthe roll shafts are mounted in housings each of which ispivotally supported on a frame in such a manner that the housing may be swung to effect any desired lateral adjustment 30 of the roll axes within the range of operation of the mill, means being providedfor holding the pivotally mounted housing in it's variably adjusted positions.

The invent-ion also contemplates the provision of roll drives which readily permit lateral adjustment of the axes of the rolls to to be made,.which also readily permit the rolls to be adjusted longitudinally. These connections include an annular driven member which surrounds each shaft and is rotatably mounted in the same housing as the shaft. To compensate for any misalignment of the shaft-and driven member bearings, such as might arise from impropersettingorununiformwearupon these bearings, a ring is arranged between the shaft and its surrounding driven member, the ring having floating engagement with each so that rotation of the driven member may be properly transmitted to the shaft irrespective of such eccentricity as there may be between their mountings. Although the driven member may be driven by any suitable motor, in the preferred. embodiment of the inven tion it is the rotor of an electric motor, the stator of which surroundsthe roll shaft.

Having reference now to the illustrative embodiment of the invention, and first to that shown in Figs. 1-5, a frame'l is shown as supporting two roll housings 2 and 3 in which there are rotatably mounted shafts 4and'5 provided on their adjacent ends with mushroom-type cross rolls-6 and '7, respectively, the axes of the roll shafts being inclined with 95 relation to each other as shown in Fig. 1, and being positioned one above the other as v shown in Fig. 2 to effect the necessary pitch action of the rolls. Since each roll housing is the same, their further description will be 109 limited principally to that shown at the right of'Figs. 1 and 2.

For pivotally supporting housing 2, frame 1 is provided with trunnions 10 and 11 winch support horizontally disposed pins 12 and 13 extending into bearings formed in the housing (Fig. 5). As here shown, the axis of this pivoted support intersects the axis of shaft 4, although, as will be presently explained in connection with another embodiment of the invention, the pivot-axis may be otherwlse disposed. The forward end of housing 2 rests indirectly upon frame 1, a liner 14 having a cylindrical lower face being interposed between the frame and the housing. Between the upper plane face of liner 14 and the lower plane face of housing 2, an additional plate-like liner or liners 15 may be inserted to raise the axis of roll 6 to any desired lateral or offset position with relation to that of roll 7. By reason of its lower cylindrical face,

v rings which lie in pockets or grooves formed in the interior of a split thrust bear ing block 21 which is slidably mounted for longitudinal movements, but keyed against rotation, in the outer end of housing 2. The rear end of thrust bearing 21 is provided with a block 22 attached to anon-rotatable screw 23, the threads of which are engaged by a sleeve 24 provided with a worm wheel 25, the arrangement being such that rotation of sleeve 24 moves screw 23 longitudinally to axially adjust shaft 4. For rotating sleeve 24, there is, as shown at the left of Figs. 1 and 2, a reversable electric motor 26, the armature shaft of which is provided with'a pinion 27 meshing with a gear 28 attached to a Worm shaft 29 which meshes with worm gear 25.

In this embodiment of the invention each roll is driven by amotor which surrounds the roll shaft. As shown in Figs. 2 and 4, the

motor comprises a rotor 35 rotatably mounted in housing2 at 36, and a stator 37 surrounding the rotor and attached to the. housing. Between therotor and shaft there is a floating connecting ring 38 which is preferably provided with diametrically disposed external projections engaging recesses or pock ets 71 formed onthe interior'of rotor 35, and with diametrically disposed interior recesses or pockets 72 at ri ht angles to formed on or firmlyfconnected to shaft 4.

.of the rotor to the shaft. connection between the shaft and rotor is projections 70, which'pockets 2, receive projections 73 truly-concentric positions, ring 38 is uniformly spaced from the shaft and rotor, and projections 70 and 73 do not extend to the bot toms of the recesses or pockets 71 and 72 in which they lie. However, this symmetry is altered to the extent that there may be misalignment between the shaft and rotor bear ings, but the floating ring nevertheless serves to properly and effectively transmit rotation Furthermore, the

such as to permit of longitudinal adjustment of the shaft in the manner previously explained.

The embodiment of the invention illustrated in Figs. 6 and 7 is essentially thesame as that shown in Figs. 1-5 as far as concerns the pivotal mounting ofthe roll housing, and the means for longitudinally adjusting the position of the roll shafts. In the mill of igs. 6 and 7 the roll shafts are driven by motors which do notsurround the roll shafts. Surrounding shaft 40 there is a driven member in the form of a gear 41 rotatably mounted in housing 42, and between this driven member and the shaft there is a floating ring43 which may be, and preferably is, connected to the shaft and driven member the same as ring 38 previously described. Gear 41 meshes with a bevel pinion 46 attached to a shaft 47, which, through a universal coupling shaft48, is driven by a suitable motor 49. As explained with reference to ring 38, floating ring 43 affords a proper and effective driving connection between driving member orgear 41 and shaft 40, and compensates for such misalignment as there may be between the bearings of shaft 40 and gear 41.

The mill shown in Figs. 8 to 11 is essentially the sameas the mills previously explained as far as concerns the longitudinal adjustments of the roll shafts, and the pivotal mounting of their housing. However, in the mill shown in Figs. 8 to 11, roll housing 55 is pivotally supported by frame 56 on a horizontal axis extending below that .of rollshaft 57, a single pivot pin 58 being used for the pivot connection. For-driving roll shaft 57, it has keyed to it an external gear 59 which meshes with an external gear 60 attached to a shaft 61, which, through a. universal coupling I shaft 62, is driven by a suitable motor 63.

As previously indicated, the mills herein provided may be used for. piercing solid billets, or for reducing the'wali thickness, in-

creasing the diameter and elongating a previously pierced or otherwise formed tubular blank. In Fig. 1 the mill is illustrated as acting upon tubular blank 65 to reduce its wall thickness and increase its diameter,- a mandrel 66, supported and positioned by a mandrel bar 67, being shown in the roll pass formed by rolls 6 and 7. For laterally adjusting roll shaft 4 for varying the pitch action of the rolls, bolts 17 (Figs. 3) are loosened, and pivotally supported housing 2 is engaged and swung upwardly by a crane, or

otherwise, so that the desired removal or substitution, or both, of liner plates may be made. When the housing is thus swung upwardly these liner plates are readily accessible from the front of the housing, and therefore it is only necessary to swing housing 2 through a relatively small angle. When the necessary adjustment of liner plates has been made, the bolts 17 are again tightened to hold the housing in its adjusted position. This same procedure is followed for adjusting roll shaft 5, and for adjusting the "roll shafts of the other mills shown herein. Each roll shaft may be independently adjusted longi-. tudinally by motor 26, whigh, through pinion 27, gear 28, worm shaft 29, worm wheel 25,

4. 'A tube forming mill, comprising a housing, a shaft provided at its end with a cross I ing, and a ring arranged between and-having fioating engagement with said shaft and rotor for causing the shaft to rotate with the rotor and for compensating for misalignment of the shaft and rotor. Y j In testimony whereof, I sign m name.

moves screw 23'forwardlyoor backwardly to similarly move block 21 together with the roll shaft. Each of these adjustments may be readily made, and when made the rolls are firmly positioned and properly driven in their adjusted position. I

According to the provisions of the atent statutes, I have explained the princip e and mode of operation of my invention, and have illustrated and described several embod i ments of it. However, I desire to have it understood that, within the scope of the a'ppended claims, the invention may be practiced otherwise than as illustrated and described. i v

i I claim as my invention: 7

1. A tube forming mill, comprising a roll housing, a shaft provided at its ends with a cross roll and rotatably mounted in said housing, an annular driving'member surrounding said shaft and rotatably mounted in said housing, and a ring arranged between and having floating engagement with said'shaft and driving member for causing the shaft to rotate with the driven member and for compensating for misalignment of the shaft and driving member. v

2. A tube-forming mill, comprising a housing, a shaft provided at its end with a cross roll and rotatably mounted in said housing, an annular driving member surroundi'ng'said shaft and rotatably mounted in said housing, and afioating ringprovided exteriorly :W-ith diametrically disposed projections engaging recesses on the interior of said driven memher and provided interiorly with diametrically disposed recesses at right-angles to said aidrecesses being engaged by pro ections, projectionson said shaft.

" ,3. -A tube forming mill, comprisinga housing, a 'shaft provided at itsend with a cross ,-roll and rotatably mounted in' said housing,

an'el'ectric motor surrounding said shaft and. including an external statorandan internal rotor rotatably mounted insaid housing, and a flo'atin driving 'co'm ection between said rotor an tshaft f" 

